Hey guys, so I occasionally get trouble codes from my rear O2 sensors since Im running high flow cats. I just clear the codes with my tuner when they show up. I was talking to my friend about them and how I am going to get the rear O2's turned off with my custom tune, and he was talking about how that wouldn't fix the problem for inspection, then I told him I would just change the tune back to stock for inspection. He said that it wouldn't matter since even though I am clearing the codes with my tuner, the inspection station can still pull up the codes through their computers when they connect to my cars ECU. He said the only way to fix the problem was with MIL eliminators, and that is what he did. He has a 98 Cobra and has the same catted X pipe as me, failed the first time with the same setup as me, just cleared the codes when they showed up, but then passed the second time around after installing the MILs. Is this true? Can the inspection stations really pull up codes from your ECU that you cleared with a tuner until the problem is actually fixed? And also would MIL eliminators do the trick do you think if that is the case? Thanks.
He's either partially correct, but doesn't really understand what's going on, or you kind of misunderstood some of what he was saying. Because that's "kind of" correct, but not really......
When you clear codes, they are gone, there's no way to recover them, so they can't do that.
Other than that, things are almost correct. The problem with inspection is that when you reset the codes or load a new tune, you're going to have a P1000 code until all the monitors are rechecked, which can take up to 60 miles, and it won't pass inpection until all the monitors are ready. During that time, it can also store "pending codes". They won't kick the CEL on yet until the rest of testing is complete, but they will show up with the scanner.
The problem with having the rear O2 sensors turned off with the tune is that it sets a "Not Ready" condition, and depending on your state, and the year of the car, depends on how many "Not Ready" conditions you can have and which they can be and still pass. Here in NC with my 2001, you can have 2 "Not Ready" conditions as still pass. But NC is pretty lenient compared to most states, I guess.
My 2 "Not Ready" conditions last year were for Catalyst Monitor (rear O2's) and EGR. And I passed.